Deposits and blockages in fluid lines are often detected when a regular flow volume of the fluid through the line in question is no longer attained. When this occurs, it is clear that there are either deposits or blockages. In order to remove these deposits, especially in the case of lengthy fluid lines or complex fluid line systems, it is advantageous to be able to determine the precise location of these deposits, so that appropriate action can be taken by mechanical means. By successively disassembling parts of the fluid line, it is possible to determine the precise location. Alternatively, it is possible to identify and to remove deposits in the fluid line in question by inserting extended pipe cleaning devices into the line in question.
However, in the case of complex fluid line systems, or where there are numerous changes in the direction or the cross-section of the line, or in cases where there are particularly solid ad hoc blockages, this cannot always be resolved within a short space of time. For example, large vehicles carrying a high volume of passengers, such as a commercial aircraft, can contain many fluid lines that can be subject to blockages. This refers to all types of fluid lines, in particular, drainage lines from toilets and washbasins. Because of the complexity and the length of the fluid lines and the fluid conduction systems in a vehicle and also the high number of additional on-board components installed in the vicinity of these fluid lines, it is not possible to trace deposits and blockages in such fluid lines by successively disassembling parts of the fluid line system, without taking the vehicle out of service for a longer period, which would not be economically viable. Any preventive clearing or cleaning of fluid lines in the manner recommended in the maintenance handbooks of commercial aircraft at rigidly prescribed intervals using chemicals that may not be universally recognised as being safe will incur additional costs in the purchase of the chemicals in question and could even be the cause of corroding the fluid lines themselves as well as the seals in and around the fluid line.
Accordingly, at least one object may be regarded as proposing a system for the detection of deposits in a fluid line, in which the successive disassembling of the fluid line in order to establish the location of deposits is not necessary. At least a further object may be to control intervals of preventive maintenance of fluid lines by means of chemicals and when necessary, that is to say, once deposits have been detected. In addition, other objects, desirable features, and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.
According to a first embodiment, a system comprises a measuring body with an ultrasonic transducer and an ultrasonic receiver and at least one evaluation unit that is connected to the ultrasonic transducer and the ultrasonic receiver. The ultrasonic transducer and the ultrasonic receiver are arranged on the measuring body. The evaluation unit is adapted for storing data of changes in the direction and the cross-section of a fluid line. At the same time, it is capable of determining periods of time between ultrasonic signals that are sent out and the signals that are received in response and of filtering the response signals that relate exclusively to the stored data of changes in cross-sections and directions of the fluid line. Lastly, from the remaining signals relating to deposits, the evaluation unit is adapted for calculating the distances between the free end of the ultrasonic transducer and the deposits.
In other words, ultrasonic signals are sent from the measuring unit into the fluid line and the resulting response signals are received. It is particularly advantageous if the ultrasonic signals can be inserted directly into the fluid line in a line axial direction, so that they essentially travel in the directional axis of the fluid line. The response signals captured by the ultrasonic receiver arise at every change of direction or bend in the line, at significantly effective changes in the cross-section of the fluid line and when deposits in the fluid line are encountered. Depending upon the severity of the case, a correspondingly strong reflected signal, hereinafter referred to as a “response signal,” is returned via the fluid line and finally captured by the ultrasonic receiver. In the event of a number of changes of geometrical shape and/or deposits being captured, the ultrasonic receiver receives a quantity of response signals, referred to below as “sequence of response signals.” The period of time between the ultrasonic signal emission and a point in time of the reflection, that is to say of the generation of a respective response signal, corresponds to the distance between the position of the ultrasonic transducer and the place at which the reflection in question occurs.
For determining the response signals that emanate exclusively from deposits, the evaluation unit is adapted for storing all data for the fluid line in question relating to all possible geometric changes of shape encountered in the fluid line in an installed state. All these geometric changes in shape can be matched to a characteristic response signal that has a characteristic duration and a characteristic amplitude. The evaluation unit is adapted for filtering out from this data set all characteristic response signals from the sequence of response signals by means of a pattern recognition or a system of difference recognition. This also means that in the response signal sequence only remain response signals that relate to deposits or blockages and not those relating to any geometric changes in form of the fluid line. From the knowledge of the periods of time elapsing between the sending of the ultrasonic signal and the capture of the remaining response signals, the location of each deposit within the fluid line can be determined. Finally, by evaluating the respective amplitude pattern of the remaining response signals, it will be possible to calculate the size and the layer thickness of the different deposits.
In another embodiment of the system, the evaluation unit is adapted for carrying out a self-calibration on the basis of the stored data. In this way, if the ultrasonic transducer and the ultrasonic receiver are not accurately positioned when the measuring body is put into position, no precise information can be obtained as to the precise location of the deposits, as the locations established depend on the relative position of the ultrasonic transducer and the ultrasonic receiver in the fluid line. On the basis of a determined response signal sequence, which is compared with the stored data containing geometric changes in the fluid line, the precise relative positions of the ultrasonic transducer and the ultrasonic receiver can be established in relation to the fluid line. These determined relative positions can be used to calibrate the evaluation unit or an algorithm executed in the latter in order to identify deposits, in that the relative positions are taken into account in the subsequent detection or already in the received response signal sequence of deposits.
It is especially preferred that the measuring body is made of an elastic material and comprises an elongated form. This allows the measuring body to be inserted into an open end of a fluid line, such as a toilet bowl, a wash basin or the like. The measuring body may be realized as a flexible hose section.
In another embodiment of the system, the evaluation unit is adapted for determining the tangential slope of response signals, i.e., the development of the amplitude over time and the envelope curve of the response signal, respectively or another significant feature and for detecting the extent of the deposits that through the determined tangential slopes.
In another embodiment of the system, the evaluation unit is adapted for generating display data for a spatially resolved representation of deposits in the fluid line. In this way, the distances from the ultrasonic transducer and the ultrasonic receiver to the deposit can both be given and marked on a graduated sale for the fluid line in question. This means that a display can be created, on which an operator can clearly see where the deposit that needs to be removed is located in the fluid line.
A further embodiment of the system is realized as a mobile, portable unit.
The ultrasonic transducer and the ultrasonic receiver can be particularly advantageously constructed as so-called ultrasonic transceivers, which, in the form of a single compact structural unit, can perform the function of emitting the ultrasonic signal and also that of receiving the response signals.
A method is also provided according to an embodiment, and a use of a system according to an embodiment in a fluid line of an aircraft.